Jessi Combs, an accomplished racer and TV personality, was killed Tuesday while trying to break her own land-speed record in Oregon. She was just 39 years old. 

Known as the "fastest woman on four wheels," Combs died while driving her jet-powered car, a North American Eagle Supersonic Speed Challenger, in the Alvord Desert. According to KTVZ, the crash happened at around 4 p.m. local time. 

Many land-speed records have been set in that desert, a dry lake bed with conditions that are perfect for driving fast. Combs herself set the four-wheeled women's record there in 2016, hitting 440 mph. 

She was attempting to break that record when she died Tuesday.

Combs was also a TV personality, appearing on many car-related shows like "Overhaulin'" and "All Girls Garage." She was also a host on a season of "MythBusters."

"I’m so so sad, Jessi Combs has been killed in a crash," tweeted former "MythBusters" host Adam Savage. "She was a brilliant & too-notch builder, engineer, driver, fabricator, and science communicator, & strove everyday to encourage others by her prodigious example. She was also a colleague, and we are lesser for her absence."

He added: "My heart goes out to her family."

Combs' team member, Terry Madden, witnessed the accident and confirmed her death in an Instagram post, calling it "horrific."

"I have never loved or been loved by anyone as much as this amazing woman @thejessicombs she was truly my unicorn and I enjoyed every single minute that I had with her. She was the most amazing spirit that I have ever or will ever know," Madden wrote.

"Unfortunately we lost her yesterday in a horrific accident, I was the first one there and trust me we did everything humanly possible to save her!!"

Further details were not immediately available. 

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